src/generic/htmllbox.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        generic/htmllbox.cpp
   3 // Purpose:     implementation of wxHtmlListBox
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     31.05.03
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 2003 Vadim Zeitlin <vadim@wxwindows.org>
   9 // License:     wxWindows license
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 // For compilers that support precompilation, includes "wx.h".
  21 #include "wx/wxprec.h"
  22
  23 #ifdef __BORLANDC__
  24     #pragma hdrstop
  25 #endif
  26
  27 #ifndef WX_PRECOMP
  28 #endif //WX_PRECOMP
  29
  30 #include "wx/htmllbox.h"
  31
  32 #include "wx/html/htmlcell.h"
  33 #include "wx/html/winpars.h"
  34
  35 // ----------------------------------------------------------------------------
  36 // private classes
  37 // ----------------------------------------------------------------------------
  38
  39 // this class is used by wxHtmlListBox to cache the parsed representation of
  40 // the items to avoid doing it anew each time an item must be drawn
  41 //
  42 // TODO: extend the class to cache more than item
  43 class wxHtmlListBoxCache
  44 {
  45 public:
  46     wxHtmlListBoxCache() { m_cell = NULL; }
  47     ~wxHtmlListBoxCache() { delete m_cell; }
  48
  49     // returns true if we already have this item cached
  50     bool Has(size_t n) const { return m_cell && n == m_item; }
  51
  52     // ensure that the item is cached
  53     void Store(size_t n, wxHtmlCell *cell)
  54     {
  55         m_item = n;
  56
  57         delete m_cell;
  58         m_cell = cell;
  59     }
  60
  61     // return the cached cell for this index or NULL if none
  62     wxHtmlCell *Get(size_t n) const
  63     {
  64         // we could be reading uninitialized m_item here but the code is still
  65         // correct
  66         return n == m_item ? m_cell : NULL;
  67     }
  68
  69 private:
  70     // the parsed representation of the cached item or NULL
  71     wxHtmlCell *m_cell;
  72
  73     // the index of the currently cached item (only valid if m_cell != NULL)
  74     size_t m_item;
  75 };
  76
  77 // ============================================================================
  78 // implementation
  79 // ============================================================================
  80
  81 // ----------------------------------------------------------------------------
  82 // wxHtmlListBox creation
  83 // ----------------------------------------------------------------------------
  84
  85 void wxHtmlListBox::Init()
  86 {
  87     m_htmlParser = NULL;
  88     m_cache = new wxHtmlListBoxCache;
  89 }
  90
  91 bool wxHtmlListBox::Create(wxWindow *parent,
  92                            wxWindowID id,
  93                            const wxPoint& pos,
  94                            const wxSize& size,
  95                            size_t countItems,
  96                            long style,
  97                            const wxString& name)
  98 {
  99     return wxVListBox::Create(parent, id, pos, size, countItems, style, name);
 100 }
 101
 102 wxHtmlListBox::~wxHtmlListBox()
 103 {
 104     delete m_cache;
 105     if ( m_htmlParser )
 106     {
 107         delete m_htmlParser->GetDC();
 108         delete m_htmlParser;
 109     }
 110 }
 111
 112 // ----------------------------------------------------------------------------
 113 // wxHtmlListBox items markup
 114 // ----------------------------------------------------------------------------
 115
 116 wxString wxHtmlListBox::OnGetItemMarkup(size_t n) const
 117 {
 118     // we don't even need to wrap the value returned by OnGetItem() inside
 119     // "<html><body>" and "</body></html>" because wxHTML can parse it even
 120     // without these tags
 121     return OnGetItem(n);
 122 }
 123
 124 void wxHtmlListBox::CacheItem(size_t n) const
 125 {
 126     if ( !m_cache->Has(n) )
 127     {
 128         if ( !m_htmlParser )
 129         {
 130             wxHtmlListBox *self = wxConstCast(this, wxHtmlListBox);
 131
 132             self->m_htmlParser = new wxHtmlWinParser;
 133             m_htmlParser->SetDC(new wxClientDC(self));
 134         }
 135
 136         wxHtmlContainerCell *cell = (wxHtmlContainerCell *)m_htmlParser->
 137                 Parse(OnGetItemMarkup(n));
 138         wxCHECK_RET( cell, _T("wxHtmlParser::Parse() returned NULL?") );
 139
 140         cell->Layout(GetClientSize().x);
 141
 142         m_cache->Store(n, cell);
 143     }
 144 }
 145
 146 // ----------------------------------------------------------------------------
 147 // wxHtmlListBox implementation of wxVListBox pure virtuals
 148 // ----------------------------------------------------------------------------
 149
 150 void wxHtmlListBox::OnDrawItem(wxDC& dc, const wxRect& rect, size_t n) const
 151 {
 152     CacheItem(n);
 153
 154     wxHtmlCell *cell = m_cache->Get(n);
 155     wxCHECK_RET( cell, _T("this cell should be cached!") );
 156
 157     // draw the selected cell in selected state
 158     if ( IsSelected(n) )
 159     {
 160         wxHtmlSelection htmlSel;
 161         htmlSel.Set(wxPoint(0, 0), cell, wxPoint(INT_MAX, INT_MAX), cell);
 162         wxHtmlRenderingState htmlRendState(&htmlSel);
 163         htmlRendState.SetSelectionState(wxHTML_SEL_IN);
 164         cell->Draw(dc, rect.x, rect.y, 0, INT_MAX, htmlRendState);
 165     }
 166     else
 167     {
 168         // note that we can't stop drawing exactly at the window boundary as then
 169         // even the visible cells part could be not drawn, so always draw the
 170         // entire cell
 171         wxHtmlRenderingState htmlRendState(NULL);
 172         cell->Draw(dc, rect.x, rect.y, 0, INT_MAX, htmlRendState);
 173     }
 174 }
 175
 176 wxCoord wxHtmlListBox::OnMeasureItem(size_t n) const
 177 {
 178     CacheItem(n);
 179
 180     wxHtmlCell *cell = m_cache->Get(n);
 181     wxCHECK_MSG( cell, 0, _T("this cell should be cached!") );
 182
 183     return cell->GetHeight() + cell->GetDescent();
 184 }
 185